original late 19th century ornamental cast bronze exterior residential "senlis" pattern doorbell backplate fabricated by the yale & towne hardware mfg. co., stamford, ct. the senlis pattern was designed by architect louis h. sullivan for the union trust building located in st. louis. although yale and towne executed other sullivan-designed hardware for various building commissions, this pattern (and another known as "parma") went on to become a "common stock" design offered in yale & towne catalogs (i.e., page 714 & 715 of the 1910 hardware catalog). the dome-shaped button housing and button were removed at some unknown point in time. intricate organic design motifs. nicely aged surface patina.